Monday, May 23, 2016

Earth observation satellite development - out of gas?

The public imagination on the issue of satellite based ground imaging is far in excess of the reality that physics permits. As the public's fantasy easily penetrates national security decision-making on technology, it is inevitable that a sense of disappointment grows with such technology. Since the technology is quite expensive, even if one has a lot of investment in that technology - one is still left groaning each time around one sees the bill for the next big-ticket item.

As the price of the next "consumable" appears on the budget, one is forced to ask the question

"Do we really need this?"

This is a valid question - clearly it is a good idea to have satellite based imagery, but does a government gain anything by maintaining a fleet of satellites? - can the mission be better achieved by private imagery suppliers and a "pay-per-view" model that allows the various national customers to purchase data as needed?

It is worthwhile to examine what the main limitations of satellite based imaging are:

1) You can't guarantee that the satellite will be able to see an arbitrary spot on the planet at an arbitrary time. Availability itself is a challenge (orbital period and dwell time are both issues) and then given the predictability of the path, it is relatively easy for opposing forces to defeat the surveillance regime.

2) Even if the satellite is overhead, you can't guarantee that the image taken will not suffer from unacceptable levels of distortion and optical artifacts (I am including any and all optical correction effects you can carry out with advanced image processing)

3) Even if you have a good image - the bandwidth to download it is not always available. This makes it hard to get timely data unless you have the intelligence and foresight to book the bandwidth ahead of time.

4) In the limit you have all of the above, you still have to deal with satellite lifetimes which can be limited by natural factors, technical defects, accidents involving space debris, and finally enemy interference.

All that weighs heavily on people who have to take decisions in such matters. These decisions were a lot easier in the early days when no such imagery was available from any other sources and the risk posed by direct overflights was significant. Now... things are different.

Obviously things have come a long way since the early days of satellite imaging. And projects like  MOIRE are interesting but we are still a long way from where the demands set by public imagination are.  Private industry has been growing capacity for this satellite related work. There has been a boom in startups with earth imaging capabilities. Theoretically one can hand things off to private players, but one has a separate set of problem keeping the startups's claims ... how should I say this delicately... "aligned with the truth".

As satellites go - one simply has to keep investing in higher and higher risk projects and that is a problem in the mission critical sphere of things. This seems undesirable in the current economic climate.

The gaps in the satellite coverage are significant and platforms like the TR-2 have to be kept active. Despite all the satellite advantages, most air forces in the world still have LOROP type mission profiles and a number of high endurance drones are being developed. These are risky missions and risky platforms but the bill seems much smaller.

If one is anyway dependent on earth based observation platforms, does it not seem sensible to focus on those and leave the entire EOS side of things to the private players?

Tuesday, May 17, 2016

Why bother about the leakage of thermonuclear weapons design information?

As indicated in the earlier posts [1][2], the intentional or unintentional leakage of design information on a TN weapon can pose a serious concern. Clearly over the decades since the first TN burn demonstration, there has been significant release of information and it has become progressively easier to come up with a TN design.

That being said - one might very well ask - "What is the big deal about a design?" - "I mean a design of a weapon is not like having an actual weapon!". You might think that is a seemingly rational stance to take on the issue.

You'd be wrong. That might have been true in the decades past, it is no longer true. And here is why....

In the past it was possible to focus exclusively on the spread of nuclear materials (a favorite past time in the non-proliferation community) ... but now with the spread of various nuclear extraction technologies and the black market in nuclear materials, the materials issue no longer limits as it once used to.

In the days of old, nations tested nuclear weapons in large atmospheric explosions. These explosions allowed weapons designers to carefully examine the interplay between design issues and engineering issues. Similarly military effects of an atmospheric explosion (which is closest to potential use-cases) could actually be studied and correlation between design yields and actual damage could be established.

No one does that kind of thing anymore. Very few nations actually test anymore.

The few that do - test underground - and require complex models to capture the actual device yield. They rely on simulations or archival data from Hiroshima and Nagasaki to capture potential military effects.

The majority of nuclear weapons states do not test. Instead they rely extensively on simulations at their national labs to explore design issues and device yields. As things stand today in the US and Russia, the number of real weaponeers who have actually designed a nuclear weapon from a blank piece of paper, seen it turned into a test device in an actual test (underground, overground, or underwater) and then subsequently supported its development and deployment into an actual arsenal - can be counted on your fingers. This most critical knowledge base is shrinking as most of these people are aging. A vast number have retired and passed on. There is no plan to replace this manpower - LANL and LLNL which cranked out 50 some designs before 1990, have since generated exactly two full designs. There are no publicly stated plans to replace the losses to the "Grey Tsunami" and physics education in mission critical fields in the US is declining.

The situation in Russia is no better. Between the economic contraction of the 90s and slow economic recovery over the last decade, the entire Russian weaponeering community has faced a major contraction due to lost funding and brain drain to more lucrative professions.

Stockpile stewardship in both countries poses significant challenges. Keeping existing weapons in good shape and designing replacements for aging elements of older designs consumes a lot of funding. Little is left afterwards for actual physical testing.

This is making both great nuclear powers heavily reliant on simulations for new design evaluation. The economics of other powers lower down on the nuclear totem pole is comparably worse. As arsenal sizes based on "simple designs" grow - the resources available for new design development shrink. (Hint Hint India and Pakistan).

This is why leakage of TN design information is a critical issue worthy of deeper exploration.

In the environment where no one can really afford to test a full yield device, the ability to demonstrate design simulation capabilities lends a sense of parity with established nuclear powers that can't be denied off hand. 

If you just try to dismiss the claim off hand - the resulting media fracas will do more to damage your national security image than it will hurt the person/persons/state making the claim. 

Now that one has explored the "why" of this - I will focus on the "how" aspect of the issue.

Monday, May 16, 2016

Compression and Criticality - a most delicate affair

So as we saw in the previous post on the issue of proliferation of knowledge relating to thermonuclear weapons design, we must proceed down two simultaneous but distinct lines of inquiry viz.

a) Has enough information leaked out about a TN device that it is possible for people to design it with minimal effort?

b) How does one live in a world where this information is no longer secret?

Let me focus on the first question in this post. There are three ways to ask this question

(a1) Can a single hyper empowered individual design a TN device from available knowledge?
(a2) Can a small group of individuals design a TN device from available knowledge?
(a3) Can a large group of individuals (corporation or state) design a TN device from available knowledge?

Now before I get into specific responses to a1, a2, a3, I want to touch upon the bigger underlying technical issue for designing a system based on complex nuclear reactions. 

At its core - any reaction ("chemical" or "nuclear")  needs to have reactants mix intimately with each other, and collide with sufficient energy to clear any energy barriers to making products. The products of the reaction typically have to be transported out of the way of newly arriving reactant species and that way the reaction can proceed in a continuous fashion till it actually runs out of reactant material. 

The big difference between "chemical" reactions (which involve changes in the electronic configuration of atoms and molecules) and "nuclear" reactions (which involve changes in the nuclear configuration of the reacting atoms) is that the amount of energy needed to make a nuclear reaction occur is much much higher than a chemical reaction. 

Atoms consist of a positively charged nucleus surrounded by a cloud of electrons. If the two nuclei have to react one must push the nuclei together and overcome the electrostatic (Coulombic) repulsion between the electron clouds and between the nuclei. This is requires applying a very large amount of force to the nuclear material.

The only reliable and demonstrated way of doing this has been to use compression. By putting pressure on the material you want to drive a nuclear reaction in, you can push the nuclei close to each other and overcome the large electrostatic repulsion between them. With the reactants now in place, the material reaches "criticality", i.e. the reactions can now proceed in a manner dictated by the local availability of the reactant species and the local outflow of the reaction products. 

The typical compression idea relies on detonating an explosive charge and then using the blast wave from that to compress a nuclear material. The explosive charge initiating the compression could be nuclear or conventional explosive but the key thing is that the blast wave produce a very symmetric shape inside the nuclear material under compression. 

If the material is not compressed for long enough for the reactions to actually take place then no significant yield can be achieved.  If the compression is not symmetric, then the nuclear material being compressed simply squirts out the weakest point in the compression front. 

Another added element of complexity is that as the reaction proceeds a lot of energy is created and it tries to leave the reaction volume. This creates a second blast wave that travels in a direction opposite to the one initiated by the compressing charge.  This wave interferes with the wave created by the first compressing charge and the resulting hydrodynamics can significantly alter the effectiveness of the compression event. As a result of this a very complex timing issue comes into play - essentially the first compression event has to line up very precisely with the anticipated rate of desirable nuclear reactions.

Compression and criticality is not exactly a marriage made in heaven. It takes a lot to get it right. This barrier exists purely in the physics of the system we are talking about, it can be overcome by sustained engineering efforts but those cost money and time. 

The ability to achieve a deliberate balance between compression and criticality in a secondary burn, requires resources that likely outside the hyper-empowered individual described in scenario a1.  Some of these resources may be available to the small group in scenario a2 but not all of them. The required resources should be available to the state-sized entity of scenario a3

One of the most crucial resources needed to design a well balanced compression-criticality based system would be simulation resources. Something like a large IAAS cloud platform could provide the level of computational power needed but one would still need to write a reliable neutron transport code and a reliable hydrodynamics code. The only highly reliable and tested codes for such things remain under lock and key at some national labs.  Codes of unknown reliability are available on the internet. As yet there is no evidence of an effort aimed at bench marking these "open source" codes against any other codes. 

So the only way that either the hyper empowered individual (a1) or the small group (a2) get access to actionable knowledge on reliable compression and criticality is via a state size entity (a3).  Such a knowledge transfer can occur voluntarily from the large entity as part of a strategic policy decision, or it can occur via hacking or infiltration. 

I will get into how one can possibly cope with this state of affairs in the next post. 

Wednesday, May 11, 2016

Is anything secret anymore? - the proliferation of nuclear weapons design physics information.

Kim Jong Un's little show and tell some months ago, brought into sharp focus the extent to which knowledge of nuclear weapons design has leaked or proliferated.

Most people know about the project that John "Truck Driver" Coster-Mullen undertook. John conducted the best public domain study of the Hiroshima and Nagasaki  packages so far.

In the public domain, there is lots of literature on the design of explosive lenses, an unnecessary level of detail about Po-Be initiators,  the equation of state of Plutonium has been published (Ara Barsamian , Lawson et. al.) and you can work out exactly how to couple that knowledge together into a simulation of the Hiroshima and Nagasaki devices (DEG Barroso).

After Kim's pictures were made public, a lot of attention in the Non-Proliferation community focused on ideas of a levitated pit design. In the public discussion that followed a great deal of information (albeit unsourced and unverifiable) leaked out about the nature of levitated pit designs. A lot guesstimates of sizes and magnitudes flew around in the discussions. Wherever possible people began to bring up V. Danilenko and his patents for compression of gases (Gorwitz) and so with each guesstimate, the belief that Kim Jong Un is theoretically capable of showing a fusion yield or a secondary burn grew.

When it comes to more advanced thermonuclear weapons, Wikipedia has an entire page dedicated to the TN designs which contains table of pressures available for secondary compression from various sources. It identifies ablation pressure as the most suitable candidate for control of secondary compression.

While the detailed discussions of how precisely to control the shape of the pressure front that compresses the secondary are limited to publications about ICF experiments (a very well regulated source),  there is a very large body of open literature about Rayleigh Taylor and Rayleigh Meshkov instabilities and studying them in confined spaces and understanding how they affect dynamic compression (again - a very well regulated source of information). Most readers of that literature will find it difficult to translate between what is written in those papers and the specific context of an advanced thermonuclear explosive so I guess the information is effectively sequestered at that point.

That being said - I wonder how long it will be before the random discussions appearing on the internet about "does aerodynamics work in space"  veer into discussions about what happens when a cloud of interstellar gas hits a spaceship moving at the near-light speeds. Hint hint - physics doesn't care if the ball is moving or the gas is moving, the physics is still the same... (thanks xkcd).

With all this where it is... one is within ones' rights to ask - "So what is born secret anymore?" 

There are two question hidden here - 

a) Has enough information leaked out about a TN device that it is possible for people to design it with minimal effort?

b) How does one live in a world where this information is no longer secret?

Both of these questions need to be answered if we are reach a resolution on the feelings of unease that naturally accompany this state of affairs. 

Thursday, May 05, 2016

"Nuclear Armageddon" - Dilip Hiro's perspective.

Outlook Magazine has carried an article by Dilip Hiro that first appeared in Tom's Dispatch. It is an unnecessarily long article, but here is the part that caught my eye,

Alarmingly, the nuclear competition between India and Pakistan has now entered a spine-chilling phase. That danger stems from Islamabad’s decision to deploy low-yield tactical nuclear arms at its forward operating military bases along its entire frontier with India to deter possible aggression by tank-led invading forces. Most ominously, the decision to fire such a nuclear-armed missile with a range of 35 to 60 miles is to rest with local commanders. This is a perilous departure from the universal practice of investing such authority in the highest official of the nation. 

When it comes to Pakistan’s strategic nuclear weapons, their parts are stored in different locations to be assembled only upon an order from the country’s leader. By contrast, tactical nukes are pre-assembled at a nuclear facility and shipped to a forward base for instant use. In addition to the perils inherent in this policy, such weapons would be vulnerable to misuse by a rogue base commander or theft by one of the many militant groups in the country.

I feel it is fair to conclude that this kind of information could only have come from two potential sources. The first source would be someone inside the Pakistani NSC and the second would be a non-Pakistani diplomatic source in Islamabad who was privy to the discussions between Gen. Raheel Sharif and US negotiators who tried to get Pakistan to step away from this in exchange for inclusion in to the Nuclear Suppliers Group. As Dilip has traditionally had good access to both groups of people, I am not surprised that he is writing about it.

I had been expecting something like this from Pakistan. The Pakistanis have been on the edge since Narendra Modi was elected Prime Minister of India. The situation (as I had alluded to in an earlier post) is analogous to what the USSR leadership found itself in when Ronald Reagan was elected President in 1980.

There has simply been too much loose talk in India about "mating" issue and confusing nonsense about moving India to a "first use" posture when the guaranteed second strike posture laid out in the Vajpayee era nuclear doctrine is practically indistinguishable from it.

When you couple that with the massive expansion in India's special weapons deployment facilities (NOT development facilities), you see that Pakistan has no choice but to get really really worried.  While a quick look at India's special weapons development facilities clearly shows that absent a major expansion at Rattehali and Challakere, India does not have the capacity to build a large number of packages, a similar peek at India's deployment facilities paints a far more startling picture.

As things stand now, in the last decade, India has seen over 400 new special weapons deployment sites appear at various airbases and military garrisons. Some of these complexes such as Ozar, Missa, Panagarh, Talegaon Dabhade, Ramgarh, Kiradu and Ralawas are stunningly large. In addition to this every major airfield now has the double ring bunker structure needed to house a special weapons capable platform.

Despite all the equipment failure issues that play out in the lay press, the IAF today mounts something like 100 sorties a day. Coupled with air-to-air refueling, it is highly possible for the IAF to maintain a well armed strategic air patrol aloft at all times. Even if I exclude the Arihant and IN capabilities, I see several hundred potential sites for *deployment* of special weapons on land alone.

It seems that while Sharm-al-shaking/dhoti-shivering/"CIA-agenting" in public the soft-spoken Prime Minister Manmohan Singh was secretly pursuing the most aggressive push towards weaponization that modern India has ever seen.  A majority of the sites that the Manmohan Singh regime constructed are deep within India.

This is a huge problem for Pakistan. Their remote sensing platforms cannot see that far into India's territory. Pakistan's AWACS program lags India's program by about a decade. The same is true for Pakistan's remote sensing capabilities - they do not have satellite imagery with sufficient resolution or sufficient time over target to guarantee the ability to keep an eye on things (for a quick discussion of what limits SATINT see this reference). Pakistan has not OTHR capability as of now (which is just as well because that has terrible issues with noise and false positives). The Pakistanis could hack India's internet backbones and try to see if they could get inside some critical information transmission system, but even if it works exactly like it does in the movies - the reality is that without verification they would be foolish to trust what is coming down that pipeline.

Basically there is NO WAY for Pakistan to stay on top of these many sites and have any confidence in the information they possess about them. 

As a result - Pakistan practically has no advanced warning capabilities that can permit it to maintain a credible first strike posture. All claims of Pakistan having some kind of escalation dominance or control in the nuclear area are far-fetched. Pakistan's "first use" posture is completely hollow. 

While some Indians might think this is a good thing - it is NOT - this is a massively unstable situation. Even in the simplest scenario that Dilip is merely hoisting a trial balloon for the Aabpara crowd - this speaks to a very alarming dynamic that has presented itself.

Deterrence stability is a living thing, you have to work had to maintain it. It is difficult to see how the old idea of deterrence stability (which emphasized sequestration and de-mating of special weapons) will survive in a situation where Pakistan feels so threatened.

We are watching the emergence of tectonic shifts in thinking about these issues in the India-Pakistan context.

Tuesday, May 03, 2016

The Chinese Graphene Story

Many of you may have been marveled by China's rise as a technological superpower. Most people in Asia saw this as a natural thing. China had always been a scientific and technological powerhouse and during the Mongol period, Chinese industrial production had expanded significantly to serve a global market. Obviously during the colonial era, China's economy suffered and declined but for over half a century, the Chinese government has been saying it will restore China to its original position as the dominant nation in the industrial and technological space.

Today China is clearly the world's manufacturing hub, China is also very rich, and has a massive military which seems to have a lot of high technology. This all seems in line with the Chinese Communist Party's narrative of restoring China to its former glory.

There is however a significant disconnect in the story. Chinese manufacturers are simply mass producing technologies invented and brought to market elsewhere. Someone else did all the heavy lifting required to invent something, bring it from lab to factory and factory to market and the Chinese are simply producing it cheaper at scale utilizing their massive labor market. This is not the mark of a nation that is *dominant* in manufacturing and technology. This kind of thing is more the sign of a follower not a leader.

One arena where China hopes to significantly change this narrative fracture is scale production of Graphene based products, One of the most lucrative products made with Graphene would be a graphene film (on glass or transparent plastic) for electronic displays (TVs, Phones, etc...) and energy storage/harvesting (solar cells, batteries etc...).  The biggest advantage of these films would be their lack of reliance on a globally narrow resource (Indium) and their ability to provide superior performance (optical and electrical) to Indium Tin Oxide.

No one in the world appears to have found a way to make it at scale. The Chinese want to change that. The scale of production that the competitive technology (Indium-Tin-Oxide on PET) is on the order of 1 bsf/y (billion square feet/year). At present an ITO film costs on the order of $1/sqft which is a pretty hefty price for a static material. That being said getting Graphene films to match this is a daunting task but if one takes a closer look at it, the Chinese may actually have a real shot at getting this done.

Most of other people trying to scale up graphene are small startups in the West and in East Asia, both these regions are economically depressed right now and can't really bring anything to market without Chinese participation. China has been buying out startups and intellectual property at a stunning rate in these nations, and given how easy it is to access production resources inside China (as opposed to from outside China), the likelihood of any of these technologies being scaled up at cost by companies in the West or in East Asia is pretty low.

Existing scale suppliers of PET/ITO, PET/PEDOT and other similar materials, currently are fairly secure in their process and market share. They are less likely (and capable) of diving into a high-risk venture like Graphene based films. As things stand today, these existing industrial players rely on cheap Chinese labor to produce their products, so if push came to shove on a purely technological front, I suspect that the Chinese would have huge leverage over these existing players.

For those of you who are like me, I am sure you are familiar with the work of Hongpo Shen. You might think that he is optimistic, but I can't find fault with any of the facts in his narrative. If you have access to actual data on the variations in the conductivity and transmission of these films obtained from a supplier in China, please share it.

I feel the story of Chinese Graphene (especially the difference between promise and real world performance) will be a great reference point for discussing China's true capacity and capability for global leadership in the technology.

ps. I am gradually shifting to a more technology focus on this blog. I have a set of big-data tools lined up for mining things I find interesting, so if you like this article, please let me know so that I can decide how to proceed with these articles.